Bücher von Sekhar Sunil Akkisetty

La topologia proposta riduce significativamente il numero di sorgenti di tensione continua, interruttori, IGBT e diodi di potenza all'aumentare del numero di livelli di tensione di uscita. Per sintetizzare i livelli massimi alla tensione di uscita, la topologia proposta è ottimizzata per vari obiettivi, come la minimizzazione del numero di interruttori, circuiti gate driver e condensatori e tensione di blocco sugli interruttori. Questo nuovo tipo di convertitore è adatto per applicazioni ad alta tensione e ad alta potenza. Questo inverter multilivello ha la capacità di sintetizzare le forme d'onda con un migliore spettro di armoniche. In questo progetto uno studio di inverter a 31 livelli basato su SVM che utilizza un numero inferiore di interruttori viene confrontato con le tecnologie sviluppate in precedenza. Il software MATLAB viene utilizzato per simulare l'inverter a 31 livelli. Inoltre, viene eseguita un'analisi comparativa per inverter multilivello simmetrici e asimmetrici con anello aperto e anello chiuso utilizzando il controller PI.

Grid tied solar inverters are designed to generate power at unity power factor which means that they have capability to produce active power only. The reactive power requirement of the load is catered by grid only. With the suddenly increase in the deployment of renewable based Distributed Energy Resources, reactive power drawn from the grid as compared to active power has increased considerably. The objective of this project is to present a local controller of reactive power to comply the new requirements asked by the transmission system operators despite the variation of ambient conditions without using extra devices. For this purpose, this project proposes a Particle Swarm Optimization Control for PV inverter to mitigate the system voltage fluctuations. Also, the method considers the loss associated with the reactive power production. Simulations are presented to assess the voltage regulation characteristics under different load conditions.

In order to maximize the efficiency of an SPV array and accomplish soft starting of apermanent magnet blushless DC motor, this study deals with a buck-boostconverter driven solar photovoltaic array fed water pumping . Current sensors, which are typically used to regulate the speed of BLDC motor, are entirely removed. A voltage-source inverter¿s changing DC-link voltage controls the BLDC motor¿s speed (VSI). This study examines how the interleaved DC-DC converter, which serves as a transitional DC-DC converter between the solar PV array and soft starting of BLDC motors, operates in a solar PV array fed water pumping system. The output ripple current of the intermediate region for recording maximum power (MPPT). In this project, the speed of a brushless DC motor has been managed by utilizing a variety of control approaches, including PI, Fuzzy and PSO optimization techniques. To get the most efficiency out of the solar array, the system is powered by a solar PV array and the MPPT technology.

The proposed topology significantly reduces the number of dc voltage sources, switches, IGBTs, and power diodes as the number of output voltage levels increases. To synthesize maximum levels at the output voltage, the proposed topology is optimized for various objectives, such as the minimization of the number of switches, gate driver circuits and capacitors, and blocking voltage on switches. This new type of converter is suitable for high voltage and high-power applications. This multilevel inverter has ability to synthesize waveforms with better harmonics spectrum. In this project a study of SVM based 31-level inverter using less number of switches are compared to the technologies previously developed. MATLAB software is used for simulate the 31-level inverter. Also, a comparison analysis is carried out for symmetrical and asymmetrical multi-level inverter with open loop as well as closed loop using PI controller.